Effect of teenage motherhood on cognitive outcomes in children: a population-based cohort study
- 1National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK
- 2Department of Paediatric Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
- 3Centre for Research on Inner City Health, The Keenan Research Centre, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada
- Correspondence to Dr Julia Morinis, Department of Paediatric Medicine, The Hospital for Sick Children, Rm. 10207, 10th Floor, Black Wing, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8;
- Received 10 July 2012
- Revised 20 August 2013
- Accepted 26 August 2013
- Published Online First 14 October 2013
Objective To examine the association between teenage motherhood and cognitive development at 5 years.
Design Data from Millennium Cohort Study, a prospective, nationally representative UK cohort of 18 818 infants born between 2000 and 2001.
Participants 12 021 (64%) mother-child pairs from white, English-speaking, singleton pregnancies were included.
Methods Cognitive ability at 5 years was measured by the British Ability Scales II. Difference in mean cognitive scores across maternal age groups was estimated using linear regression, with adjustment for potential confounders and mediators.
Results 617 (5%) children were born to mothers aged ≤18 years. Our analysis revealed that children of teenage mothers had significantly lower cognitive scores compared with children of mothers aged 25–34 years: difference in mean score for verbal ability −8.9 (−10.88 to −6.86, p<0.001); non-verbal ability −7.8 (−10.52 to −5.19, p<0.001); spatial ability −4.7 (−6.39 to −3.07, p<0.001), which is equivalent to an average delay of 11, 7 and 4 months, respectively. After adjustment for perinatal and sociodemographic factors, the effect of young maternal age on non-verbal and spatial ability mean scores was attenuated. A difference persisted in the mean verbal ability scores −3.8 (−6.34 to −1.34, p=0.003), equivalent to an average delay of 5 months.
Conclusions Results suggest that the difference observed in the initial analyses for non-verbal and spatial skills are almost entirely explained by marked inequalities in sociodemographic circumstances and perinatal risk. However, there remains a significant adverse effect on verbal abilities in the children born to teenage mothers.